SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = '665b22658429f96a99991368ad58b3fe1c2c3e0ac57feb2661810f7fd81cf273' 
  AND token = 'GR0y2ElLHxqQON/ZZvaLH3gse7sG+WWZPYav33kQkxY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}